how do you know where to put accent marks?
i can never figure out where to put those little accent marks and in the future that could be a problem on Spanish tests. 
3 Answers
Oh God, we have been down this road before here we go again! Naturally Spanish words are stressed on the second to the last syllable if the word ends in a vowel, n or s. If the word ends in any other consonant than n or s the stress falls on the last syllable. Any word where the stress falls on the syllable contrary to this rule has to have a written accent. Examples: marido= ma RI do, lunes= LU nes comen= CO men español= es pa NOL hablar= ha BLAR...Now note the words with written accents because they do not follow the rule: lápiz, Bogotá, teléfono, compañía...I hope that helps!!
If you know how to pronounce the word, say it to yourself, and if there is extra stress on a vowel in the word whilst you say it, there is probably 'un accento' (one of those little flicky things) above that letter 
It may sound silly but those "little flicky things" go always above a vowel; never ever above a consonant.
Drvicente said the rules. By the way, "compañía" has a written accent because it has a "hiatus" on it : two vowels that doesn't form a syllable. "ía".
